The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 19, 1991
Filed:
Jun. 20, 1990
Kiyomi Watanabe, Tokyo, JP;
Tetsuya Matsumoto, Tokyo, JP;
Origin Electric Co., Ltd., Tokyo, JP;
Abstract
A current detecting circuit for an X-ray tube is disclosed which includes a DC high voltage generating circuit connected across a filament and an anode of the X-ray tube and current detecting means connected in series in a filament circuit. The filament, which is at a high potential, receives a power from a secondary winding of an isolation transformer, which has sufficient dielectric strength to insulate a highest voltage generated by said DC high voltage generating circuit. A rectifier circuit is arranged to rectify a current fed from said secondary winding or another winding having same dielectric strength as that of said secondary winding, and said rectifier circuit supplies a power to a signal transmitting circuit. The signal transmitting circuit is energized, according to the current detected by said current detecting means, to transmit an output signal. The output signal is transmitted through electrically isolated transmission means to a signal receiving circuit, which is at a ground potential. In case of an X-ray tube of double-filament type having a large focal spot filament and a small focal spot filament, switching means is provided to automatically change over a resistance of a current detecting resistor, in accordance with selection of the large focal filament and the small focal spot filament.